Scientists don't have to compete with loggers, poachers, or tourists at this private biological reserve where nearly 4,000 acres of pristine rain forest have been set aside just for them. "It's one of the premier tropical forest research sites in the world," says Gary Hartshorn, an ecologist at the World Forestry Center in Portland, Oregon. This biodiversity hot spot offers an incredible array of plants and animals for scientists to study, and it's more convenient than most unspoiled forests--just a two-hour drive from Costa Rica's capital, San Jose.

The station's dormitories can house up to 80 scientists, some of whom stay for months or years collecting data and analyzing it in on-site labs. "The dining facilities are fertile ground for stimulating scientific research," says Hartshorn. Scientists with fresh ideas can walk straight into the forest from the dining hall, he says. More than 240 research papers on ecosystems, soil science and forestry come out of La Selva each year.